docs: def rho_moist(T,p,q):
      '''Density of moist air.
      T is air temperature (K)
      p is air pressure (hPa)
      q is specific humidity (hPa)
  
      returns density in kg/m3
      '''
      e = vapor_pressure_from_specific_humidity(p,q)
      w = mixing_ratio_from_vapor_pressure(p,e)
      Tv = virtual_temperature_from_mixing_ratio(T,w)
      return p*100./ Rd/Tv